Isospin mixing in the giant dipole resonance

Abstract

The amount of isospin mixing in the region of the giant dipole resonance was determined by a comparison of $\ensuremath{\alpha}$-capture reaction cross sections in self-conjugate and nonconjugate nuclei. For the two nuclei $^{24}\mathrm{Mg}$ and $^{32}\mathrm{S}$ Coulomb matrix elements $〈{V}_{c}〉=11 \mathrm{and} 4$ keV at mean excitation energies of 17.6 and 15.7 MeV, respectively, were found.